JPH0986372A - Brake system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure the stability of a vehicle by stopping or suppressing the operation of an emergency auxiliary brake system, in the disorder condition of ABS systems. SOLUTION: When an IGN SW (ignition switch) 48 is turned ON in the condition ABS systems 11 and 13 are out of order, the voltage level at the point on the downstream side of a W/L (warning switch) 47 is made Lo, and an emergency auxiliary brake ECU 24 sets an emergency auxiliary brake system in the inoperative condition by the Lo signal from an emergency auxiliary brake operation possible condition setting circuit. When a brake pedal is depressed in such a condition, the emergency auxiliary brake ECU 24 has set the emergency auxiliary brake system in the inoperative condition, even though it decides that the emergency auxiliary brake operation starting condition is accomplished, and as a result, the first and the second switch valves 17 and 19 are not operated. Consequently, since the emergency auxiliary brake is not operated, a wheel locking owing to the emergency auxiliary brake operation is not generated, and the stability of the vehicle is not hurt when the ABS systems are out of order.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention allows normal braking to be performed by a driver's operation of a brake pedal in an automobile, for example, and the brake pedal can be rapidly operated during emergency braking. At times, the present invention relates to a brake system that increases the output of the negative pressure booster by automatically introducing the atmosphere into the variable pressure chamber of the negative pressure booster to operate the emergency auxiliary brake, and in particular of the vehicle when the emergency auxiliary brake is activated. Anti-skid control for stability to eliminate wheel lock during braking (hereinafter referred to as ABS
(Also referred to as) system-dependent braking system.

[0002]

2. Description of the Related Art For example, in a brake system of a vehicle such as an automobile, a negative pressure booster is used in order to obtain a large braking force which cannot be obtained only by the pedal effort of a brake pedal or to reduce the pedal effort. The master cylinder is operated by boosting the pedal effort.

However, in such a brake system, when an emergency brake is applied due to a high risk of vehicle collision, even if the brake pedal is fully depressed, the control valve opening amount of the negative pressure booster is not so large. ,
The introduction of the atmosphere is restricted, so that the output of the vacuum booster is delayed until the braking force required for emergency braking is obtained. In addition, for example, a beginner who is unfamiliar with driving a vehicle cannot fully depress the brake pedal until the maximum braking force is reached, so that the braking force required for emergency braking cannot be obtained.

For this reason, the possibility of a vehicle collision is extremely high, and when the driver operates the emergency brake by rapidly depressing the brake pedal with a large pedal depression force, the negative pressure boosting force is forcibly applied. A brake system for operating the device up to full load (full brake) has been proposed by Japanese Patent Laid-Open No. 6-179361. In this brake system, the electronic control unit estimates the emergency brake operation by detecting a change in the operation speed of the brake pedal or the pedaling force, and the solenoid valve forcibly operates the negative pressure booster as an auxiliary brake for the emergency brake. It is a thing. According to this brake system, the driver can reliably operate the emergency auxiliary brake.

[0005]

By the way, in the above-mentioned brake system of Japanese Patent Laid-Open No. 6-179361, it is necessary to equip the ABS system, and therefore, the vehicle cannot be fully braked during emergency auxiliary braking. Stability depends on this ABS system.

Therefore, in this braking system, the AB
When the S system is out of order, only the emergency auxiliary braking system is activated and ABS is not performed, so that it is difficult to ensure the stability of the vehicle.

The present invention has been made in view of the above circumstances, and its purpose is to stabilize the vehicle by stopping or suppressing the operation of the emergency auxiliary braking system when the ABS system fails. It is to provide a brake system that can secure the.

[0008]

In order to solve the above-mentioned problems, the invention of claim 1 is directed to a brake operating member, and the brake is operated by introducing a working fluid into a working chamber by operating the brake operating member. A brake booster that boosts and outputs the operating force of the operating member, a master cylinder that is activated by the output of this brake booster to generate brake fluid pressure, and the brake fluid pressure of this master cylinder is introduced. A brake cylinder that generates a braking force, and an anti-skid control system that adjusts the brake fluid pressure of the brake cylinder corresponding to the wheel so as to eliminate the lock tendency when it is determined that the wheel tends to lock during braking. , It is determined that a predetermined emergency auxiliary brake operation start condition is satisfied based on the operation amount and the operation force of the brake operation member. Emergency in which the working fluid is further introduced into the working chamber of the brake booster to cause the brake booster to generate an output larger than the output of the brake booster corresponding to the operating force of the brake operating member. An auxiliary brake system, wherein the emergency auxiliary brake system is set to be operable only at least when the anti-skid control system is normal, and when the anti-skid control system is normal and the predetermined emergency auxiliary system is provided. The brake force is increased by further introducing the working fluid into the working chamber when it is determined that the brake operation start condition is satisfied.

According to a second aspect of the present invention, a brake operating member and a brake doubler for boosting and outputting the operating force of the brake operating member by introducing the working fluid into the working chamber by operating the brake operating member. Force device, a master cylinder that is actuated by the output of this brake booster to generate brake fluid pressure, a brake cylinder that is introduced with the brake fluid pressure of this master cylinder to generate braking force, and the wheels are locked during braking. When it is judged that there is a tendency,
An anti-skid control system for adjusting the brake fluid pressure of the brake cylinder corresponding to the wheel so as to eliminate the locking tendency, and a predetermined emergency auxiliary brake operation start condition based on the operation amount and operation force of the brake operation member. When it is determined that the above condition is satisfied, the working fluid is further introduced into the working chamber of the brake booster, and the brake booster outputs from the output of the brake booster corresponding to the operating force of the brake operating member. An emergency auxiliary braking system for generating a large output, wherein the emergency auxiliary braking system outputs the output of the brake booster when the anti-skid control system is out of order and the brake booster when the anti-skid control system is normal. The output is set to be smaller than the output of the device, and It is characterized by increasing the braking force by the fact that the working fluid further into the working chamber when the auxiliary braking start condition is determined to be satisfied.

Further, in the invention of claim 3, the brake booster is a constant pressure chamber in which a negative pressure is constantly introduced from a negative pressure source,
A negative pressure is introduced when the brake operating member is not operated and an atmosphere is introduced when the brake operating member is operated, and the atmosphere is introduced into the variable pressure chamber by partitioning the constant pressure chamber and the variable pressure chamber. A diaphragm that operates by means of the above, an internal chamber that normally communicates with the negative pressure source and that is shut off from the negative pressure source when necessary, the variable pressure chamber communicates with the internal chamber when the brake operating member is not operated, and the brake A vacuum valve that shuts off the internal chamber when the operating member is operated, an atmospheric valve that shuts off the variable pressure chamber from the atmosphere when the brake operating member is not operated, and an atmospheric valve that communicates with the atmospheric air when the brake operating member is operated, and the brake operating member An input shaft for operating and controlling the vacuum valve and the atmospheric valve by operation and an output shaft for outputting by operating the diaphragm are provided. A negative pressure booster, wherein the antiskid control system adjusts the brake fluid pressure introduced into the brake cylinder, and its wheels so that the antiskid control device eliminates the locking tendency. And an anti-skid control controller for controlling the anti-skid control device so as to adjust the brake fluid pressure of the brake cylinder, and the emergency auxiliary braking system connects the internal chamber and the negative pressure source. A normally open first on-off valve provided with a first passage and a solenoid valve that is provided in the first passage and communicates with the first passage when not operating, and shuts off the first passage when operating; And a normally closed second on-off valve provided in the second passage, the electromagnetic valve being provided in the second passage and shutting off the atmosphere when not operating and communicating with the atmosphere when operating. An operation amount detection sensor for detecting an operation amount of the brake operation member, an operation force detection sensor for detecting an operation force of the brake operation member, the operation amount and the operation force detection sensor detected by the operation amount detection sensor. An emergency auxiliary brake controller that operates both the first and second opening / closing valves when it is determined that a predetermined emergency auxiliary brake operation start condition is satisfied based on the operation force detected by And the like, the electronic control unit operates the first and second opening / closing valves to connect the variable pressure chamber to the atmosphere through the second opening / closing valve, thereby increasing the braking force.

According to a fourth aspect of the present invention, in the anti-skid control system, the downstream side is connected to the anti-skid control controller, and the upstream side is connected to a power source via an ignition switch to turn on the ignition switch. And an alarm display means for issuing an alarm when the anti-skid control system malfunctions. Further, the emergency auxiliary brake controller is provided with an emergency auxiliary brake only when the voltage on the downstream side of the alarm display means is at a level higher than a predetermined value. Emergency auxiliary brake operable state setting means for outputting an operable state setting signal, or when the voltage of the downstream side of the alarm display means is at a level lower than a predetermined value, the emergency auxiliary brake is more than when the voltage is a predetermined value or more. In order to reduce the force, the emergency auxiliary brake controller It is characterized by comprising an emergency auxiliary brake actuation suppression setting means for outputting a suppressing signal suddenly auxiliary brake force.

[0012]

In the present invention thus constructed, the brake fluid is operated by the operation of the brake operating member to introduce the working fluid into the working chamber of the brake booster and the output of the brake booster. At this time, when the emergency auxiliary brake system determines that the ABS auxiliary system is operating normally and the predetermined emergency auxiliary brake operation start condition is satisfied, the output of the brake booster is further increased by further introducing the working fluid into the operation chamber. The braking force is increased to increase the emergency auxiliary brake. If the tendency to lock the wheels is detected by the operation of the emergency auxiliary brake, the ABS
The system does ABS to adjust the braking force so that the locking tendency of this wheel is released. This ensures the stability of the vehicle when the emergency auxiliary brake is activated.

Further, when the ABS system is out of order, the emergency auxiliary brake system is set in a state in which the emergency auxiliary brake cannot be operated, or the assisting force by the emergency auxiliary brake system is suppressed more than when the ABS system is normal. As a result, the emergency auxiliary brake system does not operate the emergency auxiliary brake without introducing the working fluid into the working chamber, or the working fluid introduced into the working chamber, even if it is determined that the predetermined condition for starting the operation of the emergency auxiliary brake is satisfied. Is suppressed from the normal state of the ABS system to suppress the braking force of the emergency auxiliary brake. Therefore, the wheel lock does not occur due to the operation of the emergency auxiliary brake, and the stability of the vehicle is not deteriorated when the ABS system fails and the driver depresses the brake pedal for operating the emergency auxiliary brake.

Further, when it is not possible to determine the normality / failure of the ABS system due to the failure of the alarm display means or the disconnection of the power supply circuit to the alarm display means, the emergency auxiliary brake does not operate, that is, the emergency auxiliary brake system is safe. It comes to work on the side.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a first embodiment of a brake system according to the present invention.

As shown in FIG. 1, the brake system 1 according to the first embodiment has a brake pedal 2 and a tandem-type negative pressure booster 3 which is operated by the depression of the brake pedal 2 during normal braking to output. And a tandem master cylinder 4 that generates a brake fluid pressure in each of the two fluid chambers by the output of the negative pressure booster 3, and a brake fluid pressure generated in one fluid chamber of the tandem master cylinder 4 Of the left and right rear wheels, and the brake fluid pressure generated in the other fluid chamber of the tandem master cylinder 4 is supplied through the fluid pressure passage 8. Each of the wheel cylinders 9 and 10, the ABS device 11 disposed in both hydraulic passages 5 and 8, and the PV disposed in the hydraulic passages 5 and 8 between the tandem master cylinder 4 and the ABS device 11. 12, an ABS controller (hereinafter, also referred to as an ABS ECU) 13 for controlling the ABS device 11, a negative pressure source 15 for supplying a negative pressure to the negative pressure booster 3 via a negative pressure passage 14, and a negative pressure passage. A first variable pressure passage 16 for branching from 14 to selectively supply either the negative pressure of the negative pressure source 15 or the atmosphere to the negative pressure booster 3; A normally open first opening / closing valve 17 composed of a solenoid valve provided with a communication position and a shutoff position, and a first variable pressure passage 1 on the negative pressure booster 3 side of the first opening / closing valve 17.
A normally closed second on-off valve 19 including a second variable pressure passage 18 that communicates 6 with the atmosphere, a solenoid valve that is disposed in the second variable pressure passage 18 and that has a cutoff position and a communication position; Only the third variable pressure passage 20 branched from the passage 16 and connected to the negative pressure booster 3 and the flow of air provided from the first variable pressure passage 16 toward the negative pressure booster 3 are provided in the third variable pressure passage 20. An allowable check valve 21, a pedal force meter 22 provided on the brake pedal 2 for detecting the pedal effort, a stroke sensor 23 for detecting the stroke of the brake pedal 2,
An emergency auxiliary brake controller (hereinafter referred to as an emergency auxiliary brake controller) that outputs a control signal to the first and second opening / closing valves 17 and 19 as well as the pedal pedaling force detection signal from the pedaling force meter 22 and the pedal stroke detection signal from the stroke sensor 23 are input. Brake ECU) 24 and ABS device 1
1 or an ABS ECU 13, a warning lamp (hereinafter, also referred to as W / L) 47 that is turned on, an ignition switch (hereinafter, also referred to as IGN SW), a battery 49, and an emergency auxiliary brake operable state setting circuit 50. I have it. The hydraulic passages 8 below the ABS device 11 have two independent hydraulic passages 8 for the left and right front wheels.
It branches into a and 8b.

FIG. 2 is an enlarged sectional view showing the negative pressure booster 3. As shown in FIG. 2, the negative pressure booster 3 is the same as a conventional tandem type negative pressure booster, and includes an input shaft 25 connected to the brake pedal 2 and a front shell 26.
A center plate 28 for partitioning an internal space formed by the rear shell 27 into a front chamber and a rear chamber
And the front power piston 2 arranged in the front chamber
9 and the front chamber, which is arranged so as to be located on the rear surface of the front power piston 29, is a constant pressure chamber 30 on the front side.
Also, a front diaphragm 32 that divides into a variable pressure chamber 31 on the front side, which is the working chamber of the present invention, a rear power piston 33 disposed in the rear chamber, and a rear power piston 33 disposed so as to be located on the rear surface of the rear power piston 33. A rear diaphragm 36 that divides the rear chamber into a constant pressure chamber 34 on the rear side and a variable pressure chamber 35 on the rear side, which is a working chamber of the present invention, and a bellows 38 that is formed in the constant pressure chamber 30 on the front side to define an internal chamber 37. And a vacuum valve 39b which is closed when the brake is not operated and opened by advancing the input shaft 25 and a vacuum valve 39b which is opened when the brake is not operated and closed by advancing the input shaft 25. A constant pressure chamber 30 on the front side and a constant pressure chamber 34 on the rear side formed outside the bead portion of the front diaphragm 32.
And a constant pressure passage 40 that always communicates with each other, a fourth variable pressure passage 41 that constantly communicates with the annular space between the atmosphere valve 39a and the vacuum valve 39b, and the variable pressure chamber 35 on the rear side, and the variable pressure chamber 3 on the front side.
1 and the variable pressure chamber 35 on the rear side, a fifth variable pressure passage 42, a sixth variable pressure passage 43 that always communicates the inner chamber 37 and an annular space outside the vacuum valve 39b, and the master cylinder 4
Of the output shaft 44 for operating the piston of and the reaction disk 4 for transmitting the reaction force of the output of the output shaft 44 to the input shaft 25
5 and the rear shell 27 and the center plate 28 in an airtight and slidable manner to form fourth, fifth and sixth variable pressure passages 41, 42 and 43 and a control valve 39 and a reaction disc 45. And a valve body 46 to which the power pistons 29 and 33, the diaphragms 32 and 33, and the bellows 38 are attached.

A negative pressure passage 14 is provided in the constant pressure chamber 30 on the front side.
Is connected so that the negative pressure is constantly introduced from the negative pressure source 15. The negative pressure introduced into the constant pressure chamber 30 is further always introduced into the constant pressure chamber 34 on the rear side through the constant pressure passage 40. Also, the bellows 38
The first variable pressure passage 16 is connected to the inner chamber 37 of
When the first opening / closing valve 17 is open and the second opening / closing valve 19 is closed, negative pressure is introduced from the negative pressure source 15 into the internal chamber 37. In addition, the first on-off valve 17 is closed and the second
When the opening / closing valve 19 is open, the atmosphere flowing in through the second opening / closing valve 19 and the first variable pressure passage 16 is in the internal chamber 3
It will be introduced in 7. Further, the third variable pressure passage 20 is connected to the rear variable pressure chamber 35, and when the first open / close valve 17 is open and the second open / close valve 19 is closed, the negative pressure from the negative pressure source 15 becomes the first. The check valve 21 blocks the entry into the variable pressure chamber 35 through the variable pressure passage 20, and the atmosphere is introduced into the variable pressure chamber 35 when the first opening / closing valve 17 is closed and the second opening / closing valve 19 is opened. It is like this.

The emergency auxiliary brake ECU 24 detects the pedal depression detection signal from the stroke sensor 23 and the pedal force meter 2.
When the calculation result becomes a preset emergency auxiliary brake operation start condition based on the pedal depression force signal from 2, the emergency auxiliary brake is operated by switching the first and second opening / closing valves 17 and 19. It is designed to operate.
The emergency auxiliary brake operation start condition is, for example, when the pedal stroke speed obtained by differentiating the pedal depression detection signal from the stroke sensor 23 is equal to or more than a set value and / or when the tread force from the tread force meter 22 is equal to or more than the set value. However, the present invention is not limited to this, and any condition may be used as long as it can be estimated that the driver depresses the brake pedal 2 to operate the emergency auxiliary brake.

Then, the ABS device 11 and the ABS E
The ABS system is configured by the CU 13, and the first
Variable pressure passage 16, first and second on-off valves 17, 19, second
Variable pressure passage 18, third variable pressure passage 20, check valve 2
An emergency auxiliary brake system is configured by the pedaling force meter 22, the stroke sensor 23, and the emergency auxiliary brake ECU 24.

By the way, in such an emergency auxiliary braking system, the wheels may be locked because the negative pressure booster 3 is in a full load state when the emergency auxiliary braking is activated. The ABS system operates to adjust the braking force to secure the stability of the vehicle as in the case of the wheel lock. However, if the ABS device 11 or the ABS ECU 13 fails as described above, ABS is not performed even if the wheels are locked during the operation of the emergency auxiliary brake, and only the emergency auxiliary braking system operates, so that the stability of the vehicle is ensured. It's difficult.

Therefore, in this embodiment, when the failure of the ABS device 11 or the ABS ECU 13 is detected, the operation of the emergency auxiliary braking system is stopped, that is, AB.
Only when the S system is normal, the emergency auxiliary braking system can be operated. For that reason, in this embodiment, the ABS warning lamp 4 is used.
The voltage level on the downstream side of 7 is monitored.
The control for activating the emergency auxiliary braking system is performed only when i is set.

FIG. 3 is a diagram showing a control circuit for controlling the operation of such an emergency auxiliary brake. As shown in FIG. 3, the upstream side of the W / L 47 is ING SW4.
8 is connected to the battery 49, and its downstream side is connected to the ABS ECU 13. This W / L 47 is A when the ING SW 48 is on,
It lights up only when the BS system fails and the W / L 47 and the power supply circuit for the W / L 47 are normal.

Further, a point A on the downstream side of the W / L 47 is connected to the emergency auxiliary brake operable state setting circuit 50. The emergency auxiliary brake operable state setting circuit 50 has a comparator 51, and the point A is this comparator 5.
1 is connected to the + side terminal via a resistor R1. The negative side terminal of the comparator 51 has a voltage V which is a comparison reference value.
1 connected to the power supply. The output side of the comparator 51 is connected to the emergency auxiliary brake ECU 24 of the emergency auxiliary braking system.

The voltage level at the point A on the downstream side of the W / L 47 is as shown in Table 1 when the ING SW 48 is off.
It becomes Lo regardless of the normality or failure of the ABS system and the normality or failure of the W / L 47 or the power supply circuit for the W / L 47. When the INGSW 48 is on,
The voltage level at the point A is Hi when the ABS system is normal, and becomes Lo when the ABS system fails or the W / L 47 or the power supply circuit for the W / L 47 fails.

[0026]

[Table 1]

Then, as shown in Table 2, when the voltage level at the point A is Hi, the output of the comparator 51 becomes Hi,
The output of the comparator 51 is set to Lo when the voltage level at the point A is Lo.

[0028]

[Table 2]

When the Hi output from the comparator 51 is input, the emergency auxiliary brake ECU 24 sets the first and second opening / closing valves 17 and 19 in a switchable state.

Therefore, even if the above-described emergency auxiliary brake operation start condition is satisfied, as long as the Hi signal is not input from the emergency auxiliary brake operable state setting circuit 50,
The emergency auxiliary brake ECU 24 includes the first and second opening / closing valves 1.
No switching operation of 7, 7 is made, that is, the emergency auxiliary braking system is not set in an operable state.

The operation of the present embodiment configured as described above will be described. To drive the vehicle, the IGN SW48 is turned on to start the engine system. At this time, it is assumed that the ABS system, the W / L 47, and the power supply circuit for the W / L 47 are both normal. Therefore, in this case, the W / L 47 does not light up, the voltage level at the point A on the downstream side of the W / L 47 becomes Hi, and as shown in Table 2, the Hi signal from the emergency auxiliary brake ready state setting circuit 50 is urgent. It is supplied to the auxiliary brake ECU 24. As a result, the emergency auxiliary brake ECU 24 sets the emergency auxiliary brake system in a state in which the emergency auxiliary brake can be operated.

In this state, when the brake pedal 2 is released and the brake is not operated, the negative pressure booster 3 and the first and second opening / closing valves 17 and 19 are in the states shown in FIGS. 1 and 2. There is. In this state, when the driver depresses the brake pedal 2 to perform the normal brake operation in a state where the normal pedal stroke speed or the normal pedal depression force, that is, the condition for starting the emergency auxiliary brake operation is not satisfied, the above-mentioned conventional negative pressure is applied. The vacuum valve 39b is closed and the atmospheric valve 39a is opened to operate the normal brake as in the normal brake operation of the booster. In this case, since the emergency auxiliary brake operation start condition is not satisfied, the emergency auxiliary brake ECU 24 does not turn on the first and second opening / closing valves 17 and 19, and the emergency auxiliary brake does not operate.

When the wheels are locked during normal braking, the ABS system performs ABS to adjust the braking force of the locked wheels so that the lock is released. This ensures the stability of the vehicle. When the brake pedal 2 is released, the atmospheric valve 3 is released as in the conventional negative pressure booster.
9a is closed and the vacuum valve 39b is opened to release the normal brake.

Further, in this state, when the driver operates the emergency auxiliary brake and depresses the brake pedal 2 while the emergency auxiliary brake operation start condition is satisfied, the emergency auxiliary brake ECU 24 detects the pedaling force from the pedal force meter 22. Calculation is performed based on the signal and the stroke detection signal from the stroke sensor 23, and it is determined from the calculation result that the emergency auxiliary brake operation start condition is satisfied. At this time, since the Hi signal is input from the emergency brake operable state setting circuit 50, the emergency auxiliary brake ECU 24 switches the first and second opening / closing valves 17 and 19 to operate the emergency auxiliary brake.

As described above, when the IGN SW48 is on and the ABS system and the power supply circuits for W / L47 and W / L47 are both normal, the driver is in a state where the emergency auxiliary brake operation start condition is satisfied. When the brake pedal 2 is depressed, the emergency auxiliary brake operates reliably. Therefore, when the wheels are locked during the operation of the emergency auxiliary brake, the ABS system performs ABS to adjust the braking force of the locked wheels so that the lock is released. This ensures the stability of the vehicle.

When the driver releases his / her foot from the brake pedal 2 to release the emergency auxiliary brake, the pedaling force becomes smaller than the set value, so that the emergency auxiliary brake ECU 24 turns off both the first and second opening / closing valves 17 and 19. , And the emergency auxiliary brake is released.

It is assumed that the IGN SW48 is on, the ABS system fails, and both the W / L47 and the power supply circuit for the W / L47 are normal. Therefore, in this case, the W / L 47 is turned on, the voltage level at the point A on the downstream side of the W / L 47 becomes Lo as shown in Table 1, and the emergency auxiliary brake ready state setting circuit 50 as shown in Table 2 is obtained. Lo signal from the emergency auxiliary brake ECU 24
Is supplied to. As a result, the emergency auxiliary brake ECU 2
4 sets the emergency auxiliary brake system in a state in which the emergency auxiliary brake cannot be operated.

In order to operate the emergency auxiliary brake in this state, when the brake pedal 2 is depressed while the emergency auxiliary brake operation start condition is satisfied, the emergency auxiliary brake ECU 24 starts the emergency auxiliary brake operation in the same manner as described above. Judge that the conditions are met. However, at this time, the emergency auxiliary brake ECU 24 sets the emergency auxiliary brake system to the inoperable state by receiving the Lo signal from the emergency brake operable state setting circuit 50. Even if it is determined that the above condition is established, the first and second on-off valves 17 and 19 are not switched and the emergency auxiliary brake is not operated.

Thus, when the IGN SW48 is on, the ABS system fails and the W / L47 and W / L47
When the power supply circuits to both are normal, the emergency auxiliary brake will not operate even if the driver depresses the brake pedal 2 while the emergency auxiliary brake operation start condition is satisfied. Therefore, the wheel lock does not occur due to the operation of the emergency auxiliary brake, and the stability of the vehicle is not impaired when the driver steps on the brake pedal for the operation of the emergency auxiliary brake.

It is assumed that the IGN SW48 is on and the ABS system is normal, but the W / L47 or the power supply circuit for the W / L47 is disconnected. Therefore, in this case, the W / L 47 does not light up, the voltage level at the point A on the downstream side of the W / L 47 becomes Lo as shown in Table 1, and the emergency auxiliary brake ready state setting circuit 50 as shown in Table 2 Lo signal from the emergency auxiliary brake ECU 2
4 is supplied. As a result, the emergency auxiliary brake ECU
24 sets the emergency auxiliary brake system in a state in which the emergency auxiliary brake cannot be operated. In this case, IGN S
Even if W48 is turned on, W / L47 does not light up.
It is not possible to determine whether the S system is normal or defective, but in any case, it can be understood that even if the ABS system, the W / L 47, or the power supply circuit to the W / L 47 is few, one of them is defective.

In order to operate the emergency auxiliary brake in this state, if the brake pedal 2 is depressed while the emergency auxiliary brake operation start condition is satisfied, the emergency auxiliary brake ECU 24 starts the emergency auxiliary brake operation as described above. Judge that the conditions are met. However, at this time, since the emergency auxiliary brake ECU 24 sets the emergency auxiliary brake system in the emergency auxiliary brake inoperable state by receiving the Lo signal from the emergency brake operable state setting circuit 50, it is the same as when the ABS system fails. Even if it is determined that the emergency auxiliary brake activation start condition is satisfied, the first and second opening / closing valves 17 and 19 are not switched and the emergency auxiliary brake is not activated.

Thus, although the ABS system is normal when the IGN SW48 is on, the W / L47 or W / L
Even if the power supply circuit to L47 is out of order, even if the driver depresses the brake pedal 2 while the emergency auxiliary brake operation start condition is satisfied, the emergency auxiliary brake will not operate. Therefore, the wheel lock does not occur due to the operation of the emergency auxiliary brake, and the stability of the vehicle is not impaired when the driver steps on the brake pedal for the operation of the emergency auxiliary brake. In that case, A
Although it is not possible to determine whether the BS system is normal or defective, in such a case, the emergency auxiliary brake is not activated, that is, the emergency auxiliary braking system is activated on the safe side.

Thus, in this embodiment, the IG
N SW48 is on and ABS system, W / L47
Only when the power supply circuit to the W / L 47 is normal, the emergency auxiliary braking system becomes operable, and in other cases, the emergency auxiliary braking system becomes inoperable.

In the above embodiment, the IGN SW48 is used.
Is on and the ABS system, W / L47 and W /
When at least one of the power supply circuits to L47 is out of order, the emergency auxiliary brake enable state setting circuit 50 disables the emergency auxiliary brake system, but the present invention is not limited to this. The emergency auxiliary braking system does not necessarily have to be disabled. For example, an emergency auxiliary brake operation suppression setting circuit is provided in place of the emergency auxiliary brake operation enable state setting circuit 50, and in the case of such a failure, the emergency auxiliary brake operation suppression setting circuit causes the negative pressure doubled by the operation of the emergency auxiliary brake. It is also possible to reduce the auxiliary force of the emergency auxiliary brake to the extent that the output of the force device 3 does not cause wheel lock. That is, when at least one of the ABS system, the W / L 47, and the power supply circuit for the W / L 47 is out of order, the assisting force by the emergency auxiliary braking system can be suppressed more than in the case where it is normal. . Such control of the operation of the emergency auxiliary brake is performed by the IGN.
SW48 is on and ABS system, W / L47
And both of the power supply circuits to the W / L 47 are normal, when the emergency auxiliary brake ECU 24 determines that the emergency auxiliary brake operation start condition is satisfied and switches the first and second opening / closing valves 17 and 19 to operate. And these valves 1
This can be done by controlling the on / off time of 7,19.

Further, in the above-mentioned embodiment, although the emergency auxiliary brake operable state setting circuit 50 is provided between the downstream side of the W / L 47 and the emergency auxiliary brake ECU 24, the emergency auxiliary brake operable state setting circuit 50 is provided. May be integrated with the emergency auxiliary brake ECU 24. Similarly, the emergency auxiliary brake operation suppression setting circuit described above can also be integrated with the emergency auxiliary brake ECU 24.

Further, in the above-described embodiment, the negative pressure booster 3 using negative pressure is used as the brake booster, but the present invention is not limited to this, and hydraulic pressure or compressed air is used. It is also possible to use a brake booster using. Further, as the alarm display means, a voice alarm display means can be used in addition to the warning lamp W / L 47.

[0047]

As is apparent from the above description, according to the brake system of the present invention, when the brake operating member is operated under the condition that the predetermined emergency brake operation start condition is satisfied when the ABS system is normal, the emergency operation is performed. The auxiliary brake can be operated reliably. Further, when the lock tendency of the wheels is detected by the operation of the emergency auxiliary brake, the braking force can be adjusted by the ABS system so that the lock tendency of the wheels is released. The stability of the vehicle can be secured.

Further, when the ABS system fails, the emergency auxiliary brake is not operated or the braking force of the emergency auxiliary brake is set to AB even if the brake operating member is operated in a state where a predetermined emergency auxiliary brake operation start condition is satisfied.
Since the S system is restrained from the normal state, the wheel lock can be prevented by the emergency auxiliary brake operation, and the stability of the vehicle is not impaired.

Further, when it is not possible to determine the normality / failure of the ABS system due to the failure of the alarm display means or the disconnection of the power supply circuit to the alarm display means, the emergency auxiliary brake system is placed on the safe side that does not activate the emergency auxiliary brake. Can be set.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of a brake system according to the present invention.

FIG. 2 is a sectional view showing an example of a negative pressure booster used in the brake system of the embodiment shown in FIG.

FIG. 3 is a circuit diagram showing an emergency auxiliary brake operable state setting circuit of the embodiment shown in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Brake system, 2 ... Brake pedal, 3 ... Negative pressure booster, 4 ... Tandem master cylinder, 11 ... Anti-skid control device (ABS device), 13 ... Anti-skid control controller (ABS ECU), 14 ... Negative Pressure passage, 15 ... Negative pressure source, 16 ... First variable pressure passage, 17 ... First
On-off valve, 18 ... Second variable passage, 19 ... Second on-off valve, 20
... third variable pressure passage, 21 ... check valve, 22 ... pedal force meter, 23 ... stroke sensor, 24 ... emergency auxiliary brake control controller (emergency auxiliary brake ECU), 25
... input shaft, 35 ... rear side variable pressure chamber, 39 ... control valve, 39
a ... atmosphere valve, 39b ... vacuum valve, 47 ... warning switch (W / L), 48 ... ignition switch (IG
N SW), 49 ... Battery, 50 ... Emergency auxiliary brake operable state setting circuit, 51 ... Comparator

Claims (4)

[Claims] 1. A brake operating member, a brake booster for boosting and outputting an operating force of the brake operating member by introducing a working fluid into an operating chamber by operating the brake operating member, and the brake. It was determined that the master cylinder that is activated by the output of the booster to generate brake fluid pressure, the brake cylinder that is introduced with the brake fluid pressure of this master cylinder to generate braking force, and the wheels during braking tend to lock. At this time, an anti-skid control system that adjusts the brake fluid pressure of the brake cylinder corresponding to the wheel so as to eliminate the locking tendency, and a predetermined emergency auxiliary brake operation based on the operation amount and operation force of the brake operation member When it is determined that the start condition is satisfied, the working fluid is further introduced into the working chamber of the brake booster. Then, an emergency auxiliary brake system that causes the brake booster to generate a larger output than the output of the brake booster corresponding to the operating force of the brake operating member, the emergency auxiliary brake system comprising:
The operation is set to be operable only at least when the antiskid control system is normal, and the operation is performed when the antiskid control system is normal and when the predetermined emergency auxiliary brake operation start condition is satisfied. A brake system, wherein the braking force is increased by further introducing the working fluid into a chamber. 2. A brake operating member, a brake booster for boosting and outputting an operating force of the brake operating member by introducing a working fluid into the working chamber by operating the brake operating member, and the brake. It was determined that the master cylinder that is activated by the output of the booster to generate brake fluid pressure, the brake cylinder that is introduced with the brake fluid pressure of this master cylinder to generate braking force, and the wheels during braking tend to lock. At this time, an anti-skid control system that adjusts the brake fluid pressure of the brake cylinder corresponding to the wheel so as to eliminate the locking tendency, and a predetermined emergency auxiliary brake operation based on the operation amount and operation force of the brake operation member When it is determined that the start condition is satisfied, the working fluid is further introduced into the working chamber of the brake booster. Then, an emergency auxiliary brake system that causes the brake booster to generate a larger output than the output of the brake booster corresponding to the operating force of the brake operating member, the emergency auxiliary brake system comprising:
The output of the brake booster when the anti-skid control system fails is set to be smaller than the output of the brake booster when the anti-skid control system is normal, and the predetermined emergency auxiliary brake is used. A brake system, wherein the brake force is increased by further introducing the working fluid into the working chamber when it is determined that an operation start condition is satisfied. 3. The brake booster includes a constant pressure chamber in which a negative pressure is always introduced from a negative pressure source, a negative pressure is introduced when the brake operating member is not operated, and an atmospheric pressure is generated when the brake operating member is operated. , A diaphragm that divides the constant pressure chamber and the variable pressure chamber and operates by introducing air into the variable pressure chamber, and normally communicates with the negative pressure source and, when necessary, from the negative pressure source. An internal chamber that is shut off, a vacuum valve that communicates the variable pressure chamber with the internal chamber when the brake operating member is not operated, and that shuts off the internal chamber when the brake operating member is operated, the variable pressure chamber of the brake operating member An atmosphere valve that shuts off from the atmosphere when not operating and communicates with the atmosphere when the brake operating member is operated, and the vacuum valve and the atmosphere valve that are operated by the operation of the brake operating member. Is a negative pressure booster equipped with an input shaft for controlling the operation of the actuator and an output shaft for outputting by the operation of the diaphragm, wherein the anti-skid control system adjusts the brake fluid pressure introduced into the brake cylinder. A control device and an antiskid control controller for controlling the antiskid control device so that the antiskid control device adjusts the brake fluid pressure of the brake cylinder of the wheel so as to eliminate the locking tendency. The emergency auxiliary braking system is provided in a first passage that connects the internal chamber and the negative pressure source, and the first passage is provided in the first passage and communicates the first passage when not operating and the first passage when operating. A normally open first on-off valve composed of a solenoid valve for shutting off, a second passage connecting the variable pressure chamber and the atmosphere, and a second passage provided in the second passage. A normally closed second on-off valve that is a solenoid valve that shuts off the atmosphere when not operating and communicates with the atmosphere when operating, an operation amount detection sensor that detects an operation amount of the brake operating member, and an operation of the brake operating member A predetermined emergency auxiliary brake operation start condition is established based on an operation force detection sensor that detects force, the operation amount detected by the operation amount detection sensor, and the operation force detected by the operation force detection sensor. When judged, an emergency auxiliary brake controller that operates both the first and second opening / closing valves is provided, and the electronic control device operates the first and second opening / closing valves when necessary, such as during emergency auxiliary braking. The brake according to claim 1 or 2, wherein the brake force is increased by communicating the variable pressure chamber with the atmosphere through the second opening / closing valve. System. 4. The anti-skid control system has a further downstream side connected to the anti-skid control controller and an upstream side connected to a power source via an ignition switch, so that the anti-skid control is performed when the ignition switch is turned on. The system is provided with an alarm display means for issuing an alarm when the system malfunctions, and an emergency auxiliary brake operable state setting signal is sent to the emergency auxiliary brake controller only when the voltage on the downstream side of the alarm display means is at a level higher than a predetermined value. When the voltage on the downstream side of the emergency auxiliary brake operable state setting means for outputting or the alarm display means is at a level lower than a predetermined value, the emergency auxiliary braking force becomes smaller than when the voltage is higher than the predetermined value. , Suppress the emergency auxiliary braking force to the emergency auxiliary brake controller. The brake system according to claim 3, further comprising an emergency auxiliary brake operation suppression setting unit that outputs a braking signal.